Super spec fuel pump

[Jon Green]

Hi All,

We’re slowly making progress getting our recently purchased none running super spec back on the road.  It’s still not running but we are working our way through the wiring loom correcting and labelling up everything.  So far we have a starter motor that cranks the engine, sparks on the plugs, albeit a little weak and a fuel relay that switches the pump on and off as it should.

Unfortunately the fuel pump blows the 10 amp fuse when it is energised and does nothing else.  The question is, can the pump be removed from the sender unit or is a whole new sender and fuel pump required?

Thanks,

Jon 

[alanrichey]

Yes, easy enough to remove the fuel pump from the unit. It simply clicks in/out and is held in by the 2 tubes.   But be careful getting the replacement as there are subtle differences between models, mainly the shape of the plastic base that fits into a similarly shaped plastic base.   Having said that I managed quite easily to fit the wrong pump with a bit of bodging/bending/forcing and it still worked.   You might also have to a bit of rewiring, but it’s very straightforward, there are only 4 wires (2 for sender, 2 for pump.

 

[Jon Green]

Some progress!

Fuel to the regulator now achieved - engine cranking but plugs dry and no fuel coming out of the fuel return pipe….  Do fuel regulators fail and stop the flow of fuel or should I be moving on to check the injectors?

 

Just done a bit of research and now I’m questioning whether the fuel supply pipe is coming into the correct end of my fuel rail.  Currently it goes to the forward end of the T16 injector rail…?

Edited May 5 by Jon Green

[alanrichey]

At the forward end of the fuel rail there is a pressure valve.  Once the fuel rail reaches the correct pressure it opens and lets the fuel flow into the return hose.   I would check it isn’t stuck shut.

Also the ECU will not operate until the Crank Position Sensor tells it the engine is cranking, so you need to make sure that is working.

Have you downloaded the Superspec information pack I built ?  www.rmrsoft.com/Rover.zip

Also, have you setup my MEMS ECU Analysis program?

[Jon Green]

Hi Alan, yes all downloaded.  It now appears, from what you’ve just posted that the flow and the returns on the car have been incorrectly plumbed up.  No wonder the last owner couldn’t make it run!

Analysis program was run whilst cranking the engine… Thomas loves a bit of tech messing.

Edited May 5 by Jon Green

[alanrichey]

Good.   Would be interested to see the log file.

[Thomas]

Hi Alan,

These are all but 2 of the log files from trying to start it today, they seem pretty blank to me but maybe you'll be able to find something in there I can't.

The other 2 are more of the same.

Thanks,

Thomas

2025-05-05_17.15.txt 2025-05-05_17.14.txt 2025-05-05_17.11.txt 2025-05-05_17.02.txt 2025-05-05_16.56.txt 2025-05-05_16.53.txt

Edited May 5 by Thomas

[alanrichey]

Hi Thomas

Thanks for those, most enlightening.   There are a few things that I can see immediately

1.  It looks like the Coolant Sensor and Intake Sensor are not working (they probably don't show up on your MEMSAnalyser as I only recently updated the display).  I suggest you connect MEMSScan and check the Errors Tab, no need to start the engine, and that will show you all the errors.

2.  Your battery looks very weak.   Before cranking it is only showing 12.2V.   A fully charged battery should be at least 12.6V.   And it drops alarmingly when crank.  We have recently found another Superspec which refused to start as the battery was not delivering enough power.  We managed to start it by attaching a battery booster.    Here is a comparison between yours and mine,

3.  As I suggested before, your Crankshaft Position Sensor looks very dodgy.  Yours is very noisy,   Again here is a comparison.  Admittedly my engine actually starts, but I still think the CPS as shown should be on/off.   So worth a look I think.

Hope that helps.

Al

 

 

Edited May 6 by alanrichey

[Thomas]

Hi Alan,

MEMSScan shows a TPS error as well, we haven't looked at many of the sensors yet.

As for the battery, we've put it on charge as we had tried a few times before I logged it. We did try using jumper cables from our normal car but I don't know if that made any difference.

We'll have a look at the CPS sometime this week.

Thanks,

Thomas

[alanrichey]

OK.  Our experince with the other Superspec showed that even with the battery fully charged that even using jump cables didn't help.   But try it and see what the voltage trace looks like.

The Throttle Position Sensor (TPS) error shouldn't affect the starting, the idle system is independent of the normal running mode.   Again, we have seen a Superspec with a TPS error and what happens is that if you press the throttle too quickly the engine stalls and even if you gradually increase the throttle the engine will be running very roughly.

I assume the Crank Position Sensor (CPS) is actually used to determine the timing of the ignition, so I think the ECU signal is just an indication of whether it is working or not.   Yours might be a bit dirty but I don't know if you can take them apart to clean them or you have to replace it.

I've also found that trying to look at the Fault Codes under 'User Selected' crashes my program with an 'Overflow' error   So I would ignore the error displays and rely on the Errors Tab in MEMSScan.    I'll see if I can figure out why my program crashes.

[AndyW]

I agree with Al that your Crank Position Sensor looks very dodgy. The CPS trace for my engine is like Al's, on and a completely solid line as soon as the engine is cranked until turned off. The fact that yours turns on and off might indicate a problem. The CPS is fundamental to the engine running. Without a cranking signal MEMS won't know the engine is turning and won't operate the coil or injectors.

From my notes, here are some things to check on the CPS:

- disconnect the plug and check resistance across the 2 sensor terminals, should be 1260-1540 ohms
- check the plug and wiring is intact, and all connections are making good contact
- check the sensor is correctly fitted over the flywheel. It's held with 2 bolts and there should be a spacer underneath to give the correct distance away from the 34 reluctor poles on the flywheel
- the 2 core cable should be connected to the engine loom with a screened and earthed cable to prevent interference
- the wires should connect blue +ve to MEMS pin 31 and white -ve to pin 32 (my engine wiring colours)
- the blue wire should show 5v with ignition on, and then drop to 3v when cranking

[Jon Green]

Thants brilliant information guys, thank you.   We will be spending some time on the car tonight so will let you know how we get on.

[Thomas]

Hi,

We've done some more messing around tonight and got a few more logs, I also got a screenshot of the errors for you.

We aren't getting any fuel returning back to the tank yet, but my dad thinks it might be that the old fuel pump we're using temporarily isn't strong enough for the fuel regulator valve to open and send fuel back to the tank. There's a new fuel pump arriving tomorrow so we'll try that in soon.

When we took the spark plugs out (the file ending in 20.48) the CPS looked more like yours when we cranked the engine and when we took it out it looked pretty much new so I don't think that's a problem.

Is there anything in MEMSAnalyser that could tell us if the injectors are opening and closing?

Thanks,

Thomas

2025-05-07_20.48.txt 2025-05-07_20.43.txt 2025-05-07_20.40.txt 2025-05-07_20.35.txt

[Thomas]

Here's the screenshot sorry:

[alanrichey]

Not a pretty sight is it ?   Interesting that the Crank shaft Sync error is not showing up, but I assume that means the ECU is communicating with it OK but the readings it is getting don't make sense,

Now I look at the TPS readings I see it is showing over 100º .    If you haven't got your foot on the throttle it should be showing about 20º.   So the ECU thinks your foot is pushing the throttle down, which will affect it's settings and ability to start

There is nothing I know of that will show if the injectors are working other than physically checking them.  The problem is that the small group of people involved with this have only been able to figure out about half of the data parametres output by the ECU, mainly thorugh trial and error and disconnecting things.  .   All the official documentation was sent to China when Rover was sold, and nothing was kept.   I think even the documention for the official Rover Test Equipment didn't provide a full decode .   So one of the parameters marked 'uk' (short for 'unknown' could very well be what you are looking for.

Sorry, not much help

Al

Edited May 8 by alanrichey